1. Field of the Invention
The invention relates to a method for detecting human parvovirus B19, and reagents therefor.
2. Related Art
Human parvovirus B19 replicates in the nucleus of proliferating cells such as fetal liver cells and fetal cardiac myocytes. It is a non-enveloped virus and induces remarkable viremia in humans. It causes aplastic crisis in patients of chronic hemolytic anemia, erythema infectiosum, hydrops fetalis, febrile diseases, arthropathy, transient bone marrow failure and so on. B19 virus resists various inactivation procedures such as heat and detergent treatment.
B19 virus can be transmitted through blood, and it is important not to use infectious blood to prevent B19 virus infection by transfusion. There are two kinds of methods for detecting B19 virus infection, i.e., identification of the B19 virus itself and detection of IgM antibody specific to B19. The former methods include an indirect immunofluorescent (IF) method, a counter current immunoelectrophoresis (CIE) method, an enzyme-linked immunosorbent assay (ELISA) method, a radioimmunoassay (RIA) method, a dot blot hybridization method, and a polymerase chain reaction (PCR) assay. The latter includes the ELISA, RIA, and Western blotting methods.
The conventional methods require a long time and complicated manipulation and their sensitivity is not always sufficient. To date, B19 viremia could not be routinely checked on blood donations. Therefore, it is important to find a highly sensitive, quick and simple detection method for the B19 virus.
Brown K. E. et al have reported hemagglutination by human parvovirus B19 (Journal of General Virology, Vol. 73, p2147 to 2149, 1992). They also demonstrated that hemagglutination occurred via P-antigen (red cell membrane antigen) as a receptor for the B19 virus. (Science, Vol. 262, p114 to 117, 1993). However, while Brown et al indicate that the B19 virus causes agglutination of human red cells, they do not suggest that this phenomenon can be used for detecting the B19 virus.
The present invention provides a new method that is more sensitive and simple than previous methods.
To resolve the drawbacks in the conventional detection methods, the present inventors have realized a highly sensitive and reproducible method of detecting B19 virus using both fixed red blood cells and a buffer of pH 5.0 to 6.2.
Accordingly, the present invention provides a method for detection of human parvovirus B19 comprising the steps of bringing a sample into contact with fixed P-antigen positive red cells in a medium at pH 5.6xc2x10.6, and determining whether or not hemagglutination occurs, and a reagent for said method.